Re: [ARSCLIST] Shadowgraphed Needles

[George Brock-Nannestad <pattac@xxxxxxxx>]

From: Patent Tactics, George Brock-Nannestad

David Lennick wrote

> I picked up a lacquer this week with an unopened package of shadowgraphed
> needles attached. I wonder what shape they're in after almost 65 years? How
> many plays were you supposed to get out of them, since they were recommended
> for 15-minute transcription sides?

----- the fact that the needles were shadowgraphed is only an indication that 
their profile was checked against some (as yet non-disclosed) standard. The 
Shadowgraph was an apparatus that projected the profile onto a large, perhaps 
10" diameter ground-glass screen. On that screen the outline of the standard 
was also given, and hence it was easy to see if the needle conformed. A 
Shadowgraph was used for cutting stylii as well.

The needles, being steel, are most likely to be exactly the same shape today, 
barring rust.

The number of plays is directly dependent on the quality of the pickup the 
needles were supposed to go into - if you want to use an old pickup today, 
you must realize that deteriorated rubber will cause destruction of first the 
record and eventually the needle.

For private consumption trailing needles were usually attached to lacquer 
records. These were angled so that the risk of digging into the lacquer was 
less than zero, however the scanning loss of high frequencies was tremendous.

Kind regards,


George